20210707-003a: Norris Boat Dock SP-2020-0223DS variance packet — original pdf

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ITEM FOR ENVIRONMENTAL COMMISSION AGENDA July 7, 2021 Norris Boat Dock SP-2020-0223DS Stephen Hawkins, Aqua Permits, LLC COMMISSION MEETING DATE: NAME & NUMBER OF PROJECT: NAME OF APPLICANT OR ORGANIZATION: LOCATION: ENVIRONMENTAL REVIEW STAFF: WATERSHED: REQUEST: COUNCIL DISTRICT: District #10 1875 Westlake Dr. Lindsey Sydow, P.G. Lake Austin and Bee Creek Watershed, Water Supply Rural, Drinking Water Protection Zone Request to vary from LDC 25-8-251(C)(2)(b) to allow construction of a boat dock within 150 feet of a Canyon Rimrock Critical Environmental Feature (CEF). STAFF RECOMMENDATION: Staff recommends this variance with conditions, having determined the findings of fact to have been met. STAFF CONDITION: All construction will be completed by barge. Staff Findings of Fact Watershed Protection Department Staff Recommendations Concerning Required Findings Project Name & Case Number: Norris Boat Dock SP-2020-0223DS Ordinance Standard: Watershed Protection Ordinance Variance Request: LDC 25-8-281(C)(2)(b) - To allow construction within 150 feet of a Rimrock Critical Environmental Feature (CEF). Include an explanation with each applicable finding of fact. A. Land Use Commission variance determinations from Chapter 25-8-41 of the City Code: 1. The requirement will deprive the applicant of a privilege available to owners of similarly situated property with approximately contemporaneous development subject to similar code requirements. Yes. A variance from 25-8-281(C)(2)(b) allowing for construction of a boat dock, shoreline access, and stabilization, has been granted for similarly situated properties with approximately contemporaneous development subject to similar code. 2. The variance: a) Is not necessitated by the scale, layout, construction method, or other design decision made by the applicant, unless the design decision provides greater overall environmental protection than is achievable without the variance; Yes. No disturbance of the canyon rimrock critical environmental feature (CEF) is proposed, all proposed construction activities are to occur 75 feet downgradient of the rimrock CEF, and construction is to occur from the lakeside by barge. The proposed construction being performed from a barge provides greater overall environmental protection to the slope. b) Is the minimum deviation from the code requirement necessary to allow a reasonable use of the property;  Yes. The variance is the minimum deviation from the code requirement to allow for a reasonable use of the property. The code requires a 150-foot CEF buffer. This buffer is not being reduced. The scope of the variance is limited to allowing construction activities to occur within a CEF buffer only for the proposed boat dock replacement. c) Does not create a significant probability of harmful environmental consequences. Yes. The variance does not create significant harmful environmental consequences. The construction of the boat dock from barge will not disturb the canyon rimrock CEF. The limits of construction are at least 75 feet downgradient from the canyon rimrock CEF, and the disturbed area will be reseeded with native grasses. 3. Development with the variance will result in water quality that is at least equal to the water quality achievable without the variance. Yes, the variance will result in water quality that is at least equal to the water quality achievable without the variance. The construction activities will take place >75 feet from the canyon rimrock and all access will be by barge, which will not disturb the canyon rimrock CEF. The existing stone path will not be disturbed and will continue to be used to access the new boat dock, thus preventing any construction further up the slope closer to the canyon rimrock CEF. Staff Recommendation: Staff recommends the variance as the Findings of Fact have been met, with the staff-recommended condition that all construction be completed by barge. B. The Land Use Commission may grant a variance from a requirement of Section 25-8- 422 (Water Supply Suburban Water Quality Transition Zone), Section 25-8-452 (Water Supply Rural Water Quality Transition Zone), Section 25-8-482 (Barton Springs Zone Water Quality Transition Zone), Section 25-8-368 (Restrictions on Development Impacting Lake Austin, Lady Bird Lake, and Lake Walter E. Long), or Article 7, Division 1 ( Critical Water Quality Zone Restrictions ), after determining that: The criteria for granting a variance in Subsection (A) are met; Yes / No N/A Yes / No N/A The requirement for which a variance is requested prevents a reasonable, economic use of the entire property; 3. The variance is the minimum deviation from the code requirement necessary to allow a reasonable, economic use of the entire property. Yes / No N/A Staff Recommendation: N/A. 1. 2. Hydrogeologic Reviewer (WPD) ___________________________ Lindsey Sydow Date: Deputy Environmental Officer _____________________________ (WPD) Liz Johnston Date: Applicant Form and Findings of Fact ENVIRONMENTAL VARIANCE REQUEST ONLY DATE: May 18, 2021 CASE NUMBER: SP-2020-0223DS PROJECT NAME: Norris Boat Dock APPLICANT: David Norris S Jr, Living Trust AGENT: Aqua Permits, LLC (Stephen Hawkins) ADDRESS OF SITE: 1875 Westlake Drive COUNTY: Travis AREA: .97 acres WATERSHED: Lake Austin JURISDICTION: Austin Limited Purpose EXISTING ZONING: LA PROPOSED DEVELOPMENT: The applicant is proposing to construct a boat dock. DESCRIPTION OF VARIANCES: The applicant is requesting to vary from LDC 25-8-281(C)(2)(b) to allow construction of a boat dock within a 150-foot Critical Environmental Feature (CEF) buffer for a Rim rock CEF. Stephen HawkinsAqua Permits, LLC512-750-1402June 21, 2021 ENVIRONMENTAL COMMISSION VARIANCE APPLICATION FORM Stephen Hawkins 6504 Betty Cook Austin, Texas 78723 512-750-1402 stephen.hawkins@aquapermits.com 1875 WESTLAKE DR BLDG BD Norris Boat Dock SP-2020-0223DS Jonathan Garner PROJECT DESCRIPTION Applicant Contact Information Variance Case Information Name of Applicant Street Address City State ZIP Code Work Phone E-Mail Address Case Name Case Number Address or Location Environmental Reviewer Name Environmental Resource Management Reviewer Name Applicable Ordinance Watershed Name Watershed Classification Code 25-8-281 Critical Environmental Features / Admin Variance A Lake Austin/ Boundary, Bee Creek ☐Urban ☐ Suburban ☐Water Supply Suburban ×☐Water Supply Rural ☐ Barton Springs Zone City of Austin | Environmental Commission Variance Application Guide 1 June 21, 2021 Edwards Aquifer Recharge Zone ☐ Barton Springs Segment ☐ Northern Edwards Segment ×☐ Not in Edwards Aquifer Zones Edwards Aquifer Contributing Zone Distance to Nearest Classified Waterway ☐ Yes ☐ No × The project is to build a boat dock on Lake Austin. It is within 500 feet of Lake Austin. Water and Wastewater service to be provided by N/A Request The variance request is as follows – To allow construction on canyon rimrock CEF. This project proposes construction within the standard buffer for the canyon rimrock and is located within 500 feet of Lake Austin. square footage: Existing acreage: percentage: Proposed The site is uphill from all construction so no drainage will impact the CEF. The address of the boat dock project is 1875 Westlake Drive, Austin, TX. This property is 0.9710 acres at an elevation of 599. The vegetation is dominated by native vegetation classified as saplings and shrubs. No trees will be removed with this project, and the site will be fully restored per 609S specifications. The Upper Member of the Glen Rose Formation is relatively impermeable and described as the lower confining unit of the Edwards Aquifer (Small et al., 1996). It is about 350 to 500 feet thick. Stair-step topography is characteristic of the Upper Glen Rose Formation. The Upper Glen Rose Formation is described as yellowish tan, thinly bedded limestone and marl (Small et al., 1996). The top of the Upper Glen Rose is red-stained, lumpy, irregular, and bored, with oysters cemented onto the surface (Rose, 1972). The upper member of the Glen Rose Formation consists of alternating beds which include resistant beds of dolomite, mudstone, and limestone and non-resistant beds of calcareous clay. Provide general description of the property (slope range, elevation range, summary of vegetation / trees, summary of the geology, CWQZ, WQTZ, CEFs, floodplain, heritage trees, any other notable or outstanding characteristics of the property) City of Austin | Environmental Commission Variance Application Guide 2 June 21, 2021 Clearly indicate in what way the proposed project does not comply with current Code (include maps and exhibits) FINDINGS OF FACT This project proposes construction within the standard buffer for the canyon rimrock and is located within 500 feet of Lake Austin, so it will require a formal variance. This project proposes construction within the standard buffer for the canyon rimrock and is located within 500 feet of Lake Austin, so it will require a formal variance. Finding of facts for Land Use Commission variance to allow construction within a CEF buffer for a boat dock, shoreline access and shoreline modification must be submitted. The findings of facts are listed in LDC 25-8-41(A). A formal Land Use Commission variance fee will be paid before this comment will be cleared. As required in LDC Section 25-8-41, in order to grant a variance the Land Use Commission must make the following findings of fact: Include an explanation with each applicable finding of fact. Project: Ordinance: A. 1. 2. Land Use Commission variance determinations from Chapter 25-8-41 of the City Code: The requirement will deprive the applicant of a privilege available to owners of similarly situated property with approximately contemporaneous development subject to similar code requirements. Yes / No- Yes. Similarly situated properties, with a rimrock CEF buffer that extends to the shoreline frontage along Lake Austin, frequently contain boat docks and shoreline access. The adjacent properties have boat docks and shoreline access. The variance: a) Is not necessitated by the scale, layout, construction method, or other design decision made by the applicant, unless the design decision provides greater overall environmental protection than is achievable without the variance; Yes / No- Yes. All areas of demolition and construction within the buffer will be revegetated according to City specifications. The design of this project results in City of Austin | Environmental Commission Variance Application Guide 3 June 21, 2021 b) c) a plan that provides greater overall environmental protection than is achievable without the variance. Is the minimum deviation from the code requirement necessary to allow a reasonable use of the property; Yes / No- Yes. This buffer is not being reduced. The scope of the variance is limited to allowing construction activities to occur within a critical environmental feature buffer for only a boat dock and a pathway for shoreline access. Does not create a significant probability of harmful environmental consequences. Yes / No-Yes. The variance does not create significant harmful environmental consequences. Development with the variance will result in water quality that is at least equal to the water quality achievable without the variance. Yes / No- Yes. The construction activities will minimize disturbance to terrestrial vegetation, and all disturbed areas will be revegetated according to City specifications. B. Additional Land Use Commission variance determinations for a requirement of Section 25-8-422 (Water Quality Transition Zone), Section 25-8-452 (Water Quality Transition Zone), Article 7, Division 1 (Critical Water Quality Zone Restrictions), or Section 25-8-652 (Development Impacting Lake Austin, Lady Bird Lake, and Lake Walter E. Long): The criteria for granting a variance in Subsection (A) are met; Yes / No N/A The requirement for which a variance is requested prevents a reasonable, economic use of the entire property; Yes / No N/A The variance is the minimum deviation from the code requirement necessary to allow a reasonable, economic use of the entire property. Yes / No N/A City of Austin | Environmental Commission Variance Application Guide 4 3. 1. 2. 3. June 21, 2021 **Variance approval requires all above affirmative findings. City of Austin | Environmental Commission Variance Application Guide 5 Applicant Exhibits CASE NUMBER: SP-2020-0223DS SHEET INDEX 1) 2) Cover Sheet Demo & Proposed Site Plans Dock Plans 3) 4) Dock Elevations TREES SURVEYED Floatation Water Surface Stephen.Hawkins@AquaPermits.com 512-750-1402 Copyright Aqua Permits, LLC AQUA PERMITS Filter Cloth Skirt (Variable Depth) C:\Users\Chloe\Documents\AQUA PERMITS\TEMPLATES AND STANDARD DETAILS\AP logo.png D:/AquaPermits/AP logo.png FLOATING TURBIDITY CURTAIN Ballast Chain Channel Bottom ) n m i ( " 2 1 CONCRETE DRIVEWAY (4529 sf) POWER POLE P P P P POWER POLE P HATCHED AREA IS CEF SETBACK CONCRETE PAD EXISTING STONE BULKHEAD (11SF), NO WORK ON BULKHEAD PROPOSING DREDGING AND COFFER WALLS. MAXIMUM DREDGING IS 25 CUBIC YARDS. SEE SECTION ABOVE. DREDGE MATERIAL NOT PLACED BEHIND SHEETPILE. PRIOR TO OFFSITE DISPOSAL CONTRACTOR MUST PROVIDE ENVIRONMNETAL INSPECTOR WITH ADDRESS AND PHONE NUMBER OF SITE RECEIVING DREDGE MATERIAL. ALL WORK TO BE DONE VIA BARGE. NO SITE ACCES FOR CONSTRUCTION BY LAND. inundated corner ipf 100 YR FLOODPLAIN AS DEFINED BY FEMA AND THE COA. APPROX 498'. LAKE AUSTIN SHORELINE ELEVATION 492.8' 4 9 3 4 9 2 LOC FTC LOC FTC LOC 50% CRZ LOC LOC SYCAMORE WAS REMOVED PRIOR TO REVIEW PROCESS. FLOATING TURBIDITY CURTAIN TO DETAIN FUGITIVE SEDIMENT 18" MULCH SOCK TO DETAIN FUGITIVE SEDIMENT A 23' C O L C T F 9' C O L C T F 10' C O L C T F 4' C O L 25' FTC 17' LOC FTC LOC LOC 457 SF WITHIN THE LOC. THIS AREA REQUIRES NATIVE GRASSLAND SEEDING AND PLANTING PER COA STANDARD SPECIFICATION 609S.6, INCLUDING TOPSOIL AND SEED BED PREPARATION, TEMPORARY IRRIGATION, AND WEED MAINTANANCE. C O L C O L 50% CRZ 5 1 0 5 1 5 5 0 5 5 2 0 A 89'-31 2" D N A K C A ETB E S N 75' LA ZO " 4 4'- 3'-4" 11'-4" C O L C O L LOC 50% CRZ LOC H R H R E N O Z Y T I L A U Q R E T A W L A C I T I HR 5 R 5C 2 R H PROTECT TRUNK OF TREE T139 WITH STRAPPED ON WOOD PLANKING TO A HEIGHT OF 8' LAKE AUSTIN SHORELINE ELEVATION 492.8' 18'-3 1 16" inundated corner 50% CRZ 4 9 2 4 9 3 4 9 5 5 0 0 150' R H H R H R H R LIMITS OF CRITICAL ENVIRONMENTAL FEATURE BUFFER 100 YR FLOODPLAIN AS DEFINED BY FEMA AND THE COA. APPROX 498'. EXISTING ACCESS PATH TO BOAT DOCK CHANNEL WIDTH = 105' 20% OF 105 = 21'. DOCK PROJECTS 17' INTO CHANNEL PLAN NOTES: 1. Environmental inspector has the authoirty to add and/or modilfy erosion/sedimentation controls on site to keep project in-compliance with the City of Austin Rules and Regulations. 2. For the building permit, a signed and sealed letter shall be submitted to the City of Austin, per the Land Development Code, 25-12-3 section 1612.4, certifying that the structure is in accordance with ASCE 24, Flood Resistant Design and Construction. S-1 CRITICAL ENVIRONMENTAL FEATURE RIMROCK LEGEND 150' REQUIRED MITIGATION PLANTING: 457 SF OF DISTURBED AREA WITHIN LOC 1 NATIVE SHADE TREE AND 1 NATIVE UNDERSTORY PER 500 SF OF DISTUREBED AREA. 1 NATIVE SHRUB PER150 SF OF DISTURBED AREA. 1 7.5" SYCAMORE FOR 50% MITIGATION OF 15" SYCAMORE REMOVAL. ALL MITIGATION PLANTINGS NEED TO BE NATIVE PLANTINGS WITHIN 200 MILES. LOC LOC LOC LOC LIMITS OF CONSTRUCTION ONE 7.5", SYCAMORE (PLATANUS OCCIDENTALIS) FTC FTC FTC FTC FLOATING TURBIDITY CURTAIN SF SF SF SF SILT FENCING HR HR HAND RAIL LIGHT STATION WITH TWO BULB LIGHT FIXTURE, AMBER LIGHT EMITTING BETWEEN 112 AND 400 LUMENS ONE 1.5", 6' TALL MEXICAN BUCKEYE (UNGNADIA SPECIOSA) ONE 1.5", 6' TALL BALD CYPRESS (TAXODIUM DISTICHUM) 4 SHRUBS LINDENHEIMER MULHY) PLANTED 1' O.C.,ONE GALLON EACH LIMITS OF CRITICAL ENVIRONMENTAL FEATURE BUFFER TREES SURVEYED Total Appendix F Tree Inches Surveyed: 360" Hertiage Tree Inches Surveyed: 24" Non- Appendix F Tree Inches Surveyed: 0" Invasive Trees Inches Surveyed: 0" TREES REMOVED NO TREES REMOVED MITIGATION Total Mitigation inches planted: 3" Total replacement inches planted: 0" Total replacement ROW inches planted: 0" Total Non-mitigation Inches Planted: 0" Private inches owed to UFRF: 0" Public inches owed to UFRF: 0" COVERED CONCRETE (149sf) 2 STORY HOUSE (2985sf) COVERED CONCRETE (149sf) 2 STORY HOUSE (2985sf) DOCK WIDTH CALCULATIONS: MEASUREMENTS FOR LINEAR SHORELINE FOOTAGE ARE SHOWN ON EXISTING PLAN. 49' + 4'7" + 5'8" + 5'11" + 5'5" + 11'4" + 36'3" = 118' 2" 118' 2" x 20% = 23.5' TOTAL LENGTH OF SHORELINE: 118' 2" ALLOWABLE DOCK WIDTH (20%): 23' 6" PROPOSED DOCK WIDTH: 23' CONCRETE PAD EXISTING STONE BULKHEAD (11SF), NO WORK ON BULKHEAD 5 2 0 5 1 0 5 1 5 5 R 5C 2 R H E N O Z Y T I L A U Q R E T A W L A C I T I D N A K C A ETB E S N 75' LA ZO 100 YR FLOODPLAIN AS DEFINED BY FEMA AND THE COA. APPROX 498'. LAKE AUSTIN SHORELINE ELEVATION 492.8' EXISTING BOAT DOCK TO BE REMOVED inundated corner ipf 8'-4" 4 9 3 I N A L P D O O L F R Y 0 0 1 A O C 19'-10" 4 9 2 8'-1" 11'-5" 5'-6" 5 0 5 5'-11" 4'-7" 5'-8" 15' H R 10'-7" 5'-2" 4 9 2 50% CRZ H R 5 0 0 4 9 3 4 9 5 18'-3" LAKE AUSTIN SHORELINE ELEVATION 492.8' inundated corner H R H R N 02. PROPOSED SITE PLAN SCALE: 3/64" = 1' CONCRETE DRIVEWAY (4529 sf) POWER POLE P P P P POWER POLE P P P P P P P P P P P P P LIMITS OF CRITICAL ENVIRONMENTAL FEATURE BUFFER 100 YR FLOODPLAIN AS DEFINED BY FEMA AND THE COA. APPROX 498'. EXISTING ACCESS PATH TO BOAT DOCK S-1 CRITICAL ENVIRONMENTAL FEATURE RIMROCK LIMITS OF CRITICAL ENVIRONMENTAL FEATURE BUFFER N 01. EXISTING SITE PLAN SCALE: 3/64" = 1' K C O D T A O B E K A L T S E W 5 7 8 1 . r D e k a l t s e W 5 7 8 1 6 4 7 8 7 X T , n i t s u A Drawing Type: SITE PLAN Site Plan No. SP-2020-0223DS Sheet: 02 Revision: Description: A Revision: Description: Revision: Description: Date: 3/17/2021 Drawn By: